PHOTOACTIVATED HYDROSILATION CURING OF A CERAMIC PRECURSOR - CROSS-LINKING AND PYROLYSIS OF BRANCHED OLIGO[(METHYLSILYLENE)METHYLENE]

The complex bis(acetylacetonato)platinum(II) was activated by UV light in Liquid mixtures of oligo[(methylsilylene)methylene] (OMSM) leading to rapid solidification and the formation of polycarbosilane with a c rosslinked structure. A hydrosilation catalyst is produced by irradiat ion of this complex which promotes chain extension at OIL?SM silicon h ydride sites with the additive tetravinylsilane. Dihydridosilicon end groups on the oligomer are necessary for rapid photocuring. The crossl inked polymers were pyrolyzed under inert conditions giving 70% yields of beta-silicon carbide ceramic char with an overall carbon to silico n ratio of 1.79 to 1. Films of OMSM resin were spin-coated onto silico n wafers, cured, and pyrolyzed. Images on the film surfaces were retai ned in shape and dimension after pyrolysis. (C) 1997 Elsevier Science S.A.